Example 7 - Chapter 2 Class 9 - Introduction to Linear Polynomials (Ganita Manjari

Transcript

Example 7 Bela has ₹100 for pocket money. She spends ₹5 every day. After how many days will she be left with ₹40? From our table we can see that Amount left = Initial amount – 5 × Number of days Let Number of days = n, So our equation becomes Amount left = 100 – 5 × n We have to find after how many days will she be left with ₹40 So, putting Amount left = 40 in our equation and finding n We have Amount left = 100 – 5n 40 = 100 – 5n 40 + 5n = 100 5n = 100 – 40 5n = 60 n = 60/5 n = 12 Thus, after 12 days she will be left with ₹ 40 Day Number 0 1 2 3 4 Amount left ₹ 100